挖掘机泵控负载敏感系统设计及结构参数优化

Design and structural parameter optimization of pump-controlled load sensing system for excavator

为了提高挖掘机泵控负载敏感系统工作稳定性,设计了一种流量调节的反馈控制系统。对负载敏感阀直径、旁路阻尼孔尺寸和弹簧刚度开展综合分析,构建出泵输出流量与压力之间的函数关系,同时以AMEsim验证了流量响应的性能。研究结果表明:随着阀芯直径的增大,响应速度加快,超调量增加。当阀芯直径为10 mm时,未出现超调情况。随着弹簧刚度提高,系统发生了更明显的振荡,通常弹簧刚度设定介于15~20 N/mm范围内。当阻尼孔较小时有更长的流量阶跃响应时间,未出现超调的情况;随着阻尼孔直径的增大,流量阶跃可以在更短时间内达到稳定状态。该研究对实际挖掘机泵控负载敏感系统参数调整、工作效率提高,具有很好的实际指导意义,易于推广应用。

In order to improve the working stability of pump-controlled load sensing system of coal mine excavator,a feedback control system of flow regulation was designed.The diameter of the load-sensing valve,the size of the bypass damping hole and the spring stiffness were comprehensively analyzed to establish the functional relationship between the pump output flow and the pressure.Meanwhile,the performance of the flow response was verified by AMESim.The results show that with the increasing of diameter of spool,the response speed is faster,and the overshoot continues to increase.When the diameter of the spool is 10 mm,there is no overshoot.As the spring stiffness increases and the flow rate returns to a steady state,the system oscillates more obviously,usually in the range of 15~20 N/mm.When the damping hole is small,the step response time of flow is longer,and there is no overshoot.With the increasing of diameter of damping hole,the flow step can reach the stable state in a shorter time.The research has a very good practical guiding significance for the actual excavator pump-controlled load sensing system parameter adjustment and improving work efficiency,and is easy to be popularized and applied.